[llvm] [GlobalISel] Fold G_ICMP if possible (PR #86357)

[Shilei Tian via llvm-commits]

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@@ -82,12 +82,13 @@ body: |
     ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
     ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $vgpr1
     ; CHECK-NEXT: [[ADD:%[0-9]+]]:_(s32) = G_ADD [[COPY]], [[COPY1]]
+    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:_(s32) = COPY [[ADD]](s32)
     ; CHECK-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
     ; CHECK-NEXT: [[ICMP:%[0-9]+]]:_(s1) = G_ICMP intpred(slt), [[ADD]](s32), [[COPY]]
     ; CHECK-NEXT: [[ICMP1:%[0-9]+]]:_(s1) = G_ICMP intpred(slt), [[COPY1]](s32), [[C]]
     ; CHECK-NEXT: [[XOR:%[0-9]+]]:_(s1) = G_XOR [[ICMP1]], [[ICMP]]
     ; CHECK-NEXT: [[ZEXT:%[0-9]+]]:_(s32) = G_ZEXT [[XOR]](s1)
-    ; CHECK-NEXT: $vgpr0 = COPY [[ADD]](s32)
+    ; CHECK-NEXT: $vgpr0 = COPY [[COPY2]](s32)
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shiltian wrote:

I suppose we will have a pass to eliminate the copy later in the pipeline?

https://github.com/llvm/llvm-project/pull/86357